From a201ad17caa430aa710654fdf2e6ab4c8166f031 Mon Sep 17 00:00:00 2001
From: Darren Kenny <darren.kenny@oracle.com>
Date: Thu, 21 Jan 2021 11:38:31 +0000
Subject: [PATCH] disk/cryptodisk: Fix potential integer overflow

The encrypt and decrypt functions expect a grub_size_t. So, we need to
ensure that the constant bit shift is using grub_size_t rather than
unsigned int when it is performing the shift.

Fixes: CID 307788

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
---
 grub-core/disk/cryptodisk.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index 5037768..6883f48 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -311,10 +311,10 @@ grub_cryptodisk_endecrypt (struct grub_cryptodisk *dev,
 	case GRUB_CRYPTODISK_MODE_CBC:
 	  if (do_encrypt)
 	    err = grub_crypto_cbc_encrypt (dev->cipher, data + i, data + i,
-					   (1U << dev->log_sector_size), iv);
+					   ((grub_size_t) 1 << dev->log_sector_size), iv);
 	  else
 	    err = grub_crypto_cbc_decrypt (dev->cipher, data + i, data + i,
-					   (1U << dev->log_sector_size), iv);
+					   ((grub_size_t) 1 << dev->log_sector_size), iv);
 	  if (err)
 	    return err;
 	  break;
@@ -322,10 +322,10 @@ grub_cryptodisk_endecrypt (struct grub_cryptodisk *dev,
 	case GRUB_CRYPTODISK_MODE_PCBC:
 	  if (do_encrypt)
 	    err = grub_crypto_pcbc_encrypt (dev->cipher, data + i, data + i,
-					    (1U << dev->log_sector_size), iv);
+					    ((grub_size_t) 1 << dev->log_sector_size), iv);
 	  else
 	    err = grub_crypto_pcbc_decrypt (dev->cipher, data + i, data + i,
-					    (1U << dev->log_sector_size), iv);
+					    ((grub_size_t) 1 << dev->log_sector_size), iv);
 	  if (err)
 	    return err;
 	  break;
-- 
2.14.2

